Survey of mechanical assistance of the circulation and the present status of left-heart bypass.
The various types of mechanical circulatory assistance which recently have been developed are described. The techniques which appear to be most promising for clinical application are: veno-arterial bypass with oxygenation, synchronous arterial assistance, and closed-chest left-heart bypass.The effects of a left ventricular bypass on central hemodynamics and the oxygen requirements of the left ventricle are described. A bypass of 90% of the left ventricular output brings about a 30% reduction in the left ventricular myocardial oxygen requirement. Left atrial pressure is reduced. The central aortic mean pressure, the pulmonary artery pressure, and the right atrial pressure are not changed.
D000818:Animals; D001243:Assisted Circulation; D006328:Cardiac Catheterization / Q000295:instrumentation; D004285:Dogs; D006439:Hemodynamics; D006801:Humans